“We build a land of opportunity,” he insisted. But in the letter, he specifically suggested to Herman Van Rompuy that offshore vehicles used for what high-end financial advisers call “inheritance planning” might best be left alone. Cameron and Osborne’s supposedly exacting approach to public finances obviously had its limits. And the prime minister clearly had a keen sense of his core constituency. As one wag put it on Twitter this week, “How fortunate for people with money in offshore trusts that the prime minister went out to bat for them.” Quite so.